Method of reducing lung size

ABSTRACT

A device, system, and method provides for lung size reduction by permanently collapsing at least a portion of a lung. The lung portion may be collapsed by obstructing the air passageway which communicates the lung portion to be collapsed. The air passageway may be obstructed by an obstructing member which precludes airflow in either direction or with a one-way valve which permits air to be exhaled from the lung portion while precluding air from being inhaled into the lung portion. In addition, a vacuum may be pulled within the lung portion to be collapsed for collapsing the lung portion and while the lung portion is collapsed the obstructing member may be placed in the air passageway to maintain the lung portion in a permanently collapsed state.

This is a division of co-pending application Ser. No. 09/379,972, filedAug. 24, 1999.

BACKGROUND OF THE INVENTION

The present invention is generally directed to a device, system, andmethod for treating Chronic Obstructive Pulmonary Disease (COPD). Thepresent invention is more particularly directed to such a device, systemand method which provide lung size reduction without requiring invasivesurgery.

Chronic Obstructive Pulmonary Disease (COPD) has become a major cause ofmorbidity and mortality in the United States over the last threedecades. COPD is characterized by the presence of airflow obstructiondue to chronic bronchitis or emphysema. The airflow obstruction in COPDis due largely to structural abnormalities in the smaller airways.Important causes are inflammation, fibrosis, goblet cell metaplasia, andsmooth muscle hypertrophy in terminal bronchioles.

The incidence, prevalence, and health-related costs of COPD are on therise. Mortality due to COPD is also on the rise. In 1991 COPD was thefourth leading cause of death in the United States and had increased 33%since 1979.

COPD affects the patient's whole life. It has three main symptoms:cough; breathlessness; and wheeze. At first, breathlessness may benoticed when running for a bus, digging in the garden, or walking uphill. Later, it may be noticed when simply walking in the kitchen. Overtime, it may occur with less and less effort until it is present all ofthe time.

COPD is a progressive disease and currently has no cure. Currenttreatments for COPD include the prevention of further respiratorydamage, pharmacotherapy, and surgery. Each is discussed below.

The prevention of further respiratory damage entails the adoption of ahealthy lifestyle. Smoking cessation is believed to be the single mostimportant therapeutic intervention. However, regular exercise and weightcontrol are also important. Patients whose symptoms restrict their dailyactivities or who otherwise have an impaired quality of life may requirea pulmonary rehabilitation program including ventilatory muscle trainingand breathing retraining. Long-term oxygen therapy may also becomenecessary.

Pharmacotherapy may include bronchodilator therapy to open up theairways as much as possible or inhaled β-agonists. For those patientswho respond poorly to the foregoing or who have persistent symptoms,Ipratropium bromide may be indicated. Further, courses of steroids, suchas corticosterocds, may be required. Lastly, antibiotics may be requiredto prevent infections and influenza and pheumococcal vaccines may beroutinely administered. Unfortunately, there is no evidence that early,regular use of pharmacotherapy will alter the progression of COPD.

About 40 years ago, it was first postulated that the tethering forcethat tends to keep the intrathoracic airways open was lost in emphysemaand that by surgically removing the most affected parts of the lungs,the force could be partially restored. Although the surgery was deemedpromising, the procedure was abandoned.

The lung volume reduction surgery (LVRS) was later revived. In the early1990's, hundreds of patients underwent the procedure. However, theprocedure has fallen out of favor due to the fact that Medicare stoppingreimbursing for LVRS. Unfortunately, data is relatively scarce and manyfactors conspire to make what data exists difficult to interpret. Theprocedure is currently under review in a controlled clinical trial.However, what data does exist tends to indicate that patients benefitedfrom the procedure in terms of an increase in forced expiratory volume,a decrease in total lung capacity, and a significant improvement in lungfunction, dyspnea, and quality of life.

Improvements in pulmonary function after LVRS have been attributed to atleast four possible mechanisms. These include enhanced elastic recoil,correction of ventilation/perfusion mismatch, improved efficiency ofrespiratory muscaulature, and improved right ventricular filling.

Lastly, lung tranplantation is also an option. Today, COPD is the mostcommon diagnosis for which lung transplantation is considered.Unfortunately, this consideration is given for only those with advancedCOPD. Given the limited availability of donor organs, lung transplant isfar from being available to all patients.

In view of the foregoing, there in a need in the art for a new andimproved therapy for COPD. More specifically, there is a need for such atherapy which provides more permanent results than pharmacotherapy whilebeing less invasive and traumatic than LVRS. The present invention isdirected to a device, system, and method which provide such an improvedtherapy for COPD.

SUMMARY OF THE INVENTION

The present invention provides a method of reducing the size of a lungincluding the step of permanently collapsing at least a portion of thelung. In accordance with a first embodiment, the lung may be collapsedby obstructing an air passageway communicating with the lung portion tobe collapsed. The air passageway may be obstructed by placing anobstructing member in the air passageway. The obstructing member may bea plug-like device which precludes air flow in both directions or aone-way valve which permits air to be exhaled from the lung portion tobe collapsed while precluding air from being inhaled into the lungportion. Once the air passageway is sealed, the residual air within thelung will be absorbed over time to cause the lung portion to collapse.

In accordance with a further embodiment of the present invention, thelung portion may be collapsed by inserting a conduit into the airpassageway communicating with the lung portion to be collapsed, pullinga vacuum in the lung portion through the conduit to collapse the lungportion, and maintaining the lung portion in a collapsed state. The lungportion may be maintained in a collapsed state by sealing the airpassageway with an obstructing member or by placing a one-way valve inthe air passageway. To efficiently pull the vacuum in the lung portionto be collapsed, the space between the outer surface of the conduit andthe inner surface of the air passageway may be sealed as the vacuum ispulled. Preferably, the air passageway is sealed while the lung portionis collapsed.

The present invention further provides a device for reducing the size ofa lung. The device includes an obstructing member insertable into an airpassageway communicating with a portion of the lung to be reduced insize and having an inner dimension. The obstructing member has an outerdimension for continuous contact with the air passageway inner dimensionand sealing the air passageway upon placement in the air passageway forcollapsing the portion of the lung and reducing the size of the lung.The obstructing member may be formed of resilient material so as to becollapsible for initial insertion into the air passageway in a collapsedcondition and releasable to define the outer dimension upon placement inthe air passageway. In accordance with a further embodiment of thepresent invention, the obstructing member may include a one-way valve topermit exhaled air to flow from the lung portion while precludinginhaled air from flowing into the lung portion.

The present invention further provides a system for reducing the size ofa lung. This system includes a conduit configured to be passed down atrachea, into a bronchus communicating with the trachea, and into an airpassageway communicating the bronchus with a lung portion to be reducedin size. The system further includes an obstructing member configured tobe guided through the conduit into the air passageway for placement inthe air passageway and sealing the air passageway for collapsing thelung portion. The conduit preferably has an outer dimension smaller thanthe inner dimension of the passageway and a sealing member seals thespace between the conduit outer dimension and the air passageway innerdimension as the vacuum is pulled the system may further include avacuum source for pulling a vacuum in the lung portion through theconduit prior to placement of the obstructing member. The sealing membermay be an inflatable member. The conduit may include a first channelpulling the vacuum and for guiding the obstructing member into positionand a second channel for inflating the inflatable sealing member.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the present invention which are believed to be novel areset forth with particularity in the appended claims. The invention,together with further objects and advantages thereof, may best beunderstood by making reference to the following description taken inconjunction with the accompanying drawings, in the several figures ofwhich like referenced numerals identify identical elements, and wherein:

FIG. 1 is a simplified sectional view of a thorax illustrating a healthyrespiratory system;

FIG. 2 is a sectional view similar to FIG. 1 but illustrating arespiratory system suffering from COPD and the execution of a first stepin treating the COPD condition by reducing the size of a lung portion inaccordance with the present invention;

FIG. 3 is a perspective view, partly in section, and to an enlargedscale, illustrating an intermediate step in the treatment;

FIG. 4 is a partial perspective view of a conduit which may be utilizedin practicing the present invention;

FIG. 5 is a perspective view, to an enlarged scale, illustrating theguiding of an obstructing member through the conduit for sealing a lungportion in accordance with the present invention;

FIG. 6 is a partial exploded view of FIG. 5;

FIG. 7 is a perspective view, partly in section, and to an enlargescale, illustrating an obstructing member positioned in an airpassageway for sealing the lung portion;

FIG. 8 is a perspective view, to an enlarged scale, of an obstructingmember configured in accordance with the present invention;

FIG. 9 is a perspective view, to an enlarged scale, of the obstructingmember of FIG. 8 having a reinforcing rib;

FIG. 10 is a perspective view, to an enlarged scale, illustrating theobstructing member of FIG. 6 in a collapsed condition in accordance withfurther aspects of the present invention;

FIG. 11 is a perspective view, to an enlarged scale, of anotherobstructing member embodying the present invention in the form of aone-way valve;

FIG. 12 is a sectional view, to an enlarged scale, of another one-wayvalve obstructing member embodying the present invention in a closedposition; and

FIG. 13 is a sectional view, to an enlarged scale, of the one-way valveof FIG. 12 illustrated in an open condition.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, it is a sectional view of a healthy respiratorysystem. The respiratory system 20 resides within the thorax 22 whichoccupies a space defined by the chest wall 24 and the diaphragm 26.

The respiratory system 20 includes the trachea 28, the left mainstembronchus 30, the right mainstem bronchus 32, the bronchial branches 34,36, 38, 40, and 42 and sub-branches 44, 46, 48, and 50. The respiratorysystem 20 further includes left lung lobes 52 and 54 and right lunglobes 56, 58, and 60. Each bronchial branch and sub-branch communicateswith a respective different portion of a lung lobe, either the entirelung lobe or a portion thereof. As used herein, the term “airpassageway” is meant to denote either a bronchial branch or sub-branchwhich communicates with a corresponding individual lung lobe or lunglobe portion to provide inhaled air thereto or conduct exhaled airtherefrom.

Characteristic of a healthy respiratory system is the arched or inwardlyarcuate diaphragm 26. As the individual inhales, the diaphragm 26straightens to increase the volume of the thorax 22. This causes anegative pressure within the thorax. The negative pressure within thethorax in turn causes the lung lobes to fill with air. When theindividual exhales, the diaphragm returns to its original archedcondition to decrease the volume of the thorax. The decreased volume ofthe thorax causes a positive pressure within the thorax which in turncauses exhalation of the lung lobes.

In contrast to the healthy respiratory system of FIG. 1, FIG. 2illustrates a respiratory system suffering from COPD. Here it may beseen that the lung lobes 52, 54, 56, 58, and 60 are enlarged and thatthe diaphragm 26 is not arched but substantially straight. Hence, thisindividual is incapable of breathing normally by moving the diaphragm28. Instead, in order to create the negative pressure in the thorax 22required for breathing, this individual must move the chest walloutwardly to increase the volume of the thorax. This results ininefficient breathing causing these individuals to breathe rapidly withshallow breaths.

It has been found that the apex portion 62 and 66 of the upper lunglobes 52 and 56, respectively, are most affected by COPD. Hence, thepreferred embodiment will be described for treating the apex 66 of theright, upper lung lobe 56. However, as will be appreciated by thoseskilled in the art, the present invention may be applied to any lungportion without departing from the present invention.

The device, system, and method of the present invention treats COPD byderiving the benefits of lung volume reduction surgery without the needof performing lung volume reduction surgery. As will be seenhereinafter, the present invention contemplates permanent collapse of alung portion or lung portions most affected. This leaves extra volumewithin the thorax for the diaphragm to assume its arched state foracting upon the remaining healthier lung tissue. As previouslymentioned, this should result in improved pulmonary function due toenhanced elastic recoil, correction of ventilation/perfusion mismatch,improved efficiency of respiratory musculature, and improved rightventricle filling.

In accordance with this embodiment of the present invention, the COPDtreatment is initiated by feeding a conduit or catheter 70 down thetrachea 28, into the right mainstem bronchus 32, into the bronchialbranch 42 and into and terminating within the sub-branch 50. Thesub-branch 50 is the air passageway which communicates with the lungportion 66 to be treated.

The catheter 70 is preferably formed of flexible material such aspolyethylene. Also, the catheter 70 is preferably preformed with a bend72 to assist the feeding of the catheter from the right mainstembronchus 32 into the bronchial branch 42.

Referring now to FIG. 3, here it may be seen that the catheter includesan inflatable sealing member 74. The inflatable sealing member 74 isinflated within the sub-branch 50 to seal the space in-between the innerdimension 51 of the passageway 50 and the outer dimension 75 of thecatheter 70. For inflating the inflatable member 74 and pulling a vacuumwithin lung portion 66, the catheter 70 is coupled to a pump 80. As maybe seen in FIG. 4, the catheter 70 includes a main channel 82 throughwhich the vacuum in lung portion 66 is pulled and a minor channel 84which is utilized for inflating the inflatable member 74.

To establish the vacuum in lung portion 66, the inflatable member 74 isfirst inflated. Thereafter, the vacuum is pulled through the mainchannel 82 of the catheter 70 to pull the vacuum in lung portion 66.

Referring now to FIG. 5, here it may be seen that the lung portion 66,due to the vacuum pulled by the pump 80 and catheter 70 of FIG. 3, hascollapsed from its initial state indicated by the dashed line 86 to thesolid line 88. With the lung portion 66 thus collapsed, and while thelung portion 66 is collapsed, an obstructing member 90 is guided throughthe main channel of the conduit 70 by a stylet wire 92. This may be seenin greater detail in FIG. 6. As will be seen hereinafter with specificreference to FIGS. 8-13, the obstructing or sealing member 90 is formedof resilient or collapsible material to enable the obstructing member 90to be fed through the conduit 70 in a collapsed state. The stylet 92 isused to push the obstructing member 90 to the end 77 of the catheter 70for placing the obstructing member 90 within the air passageway 50adjacent to the lung portion 66 to be permanently collapsed.

FIG. 7 illustrates the obstructing or sealing member in place within theair passageway 50. The sealing member 90 has expanded upon placement inthe air passageway 50 to seal the air passageway 50. This causes thelung portion 66 to be maintained in a permanently collapsed state.

More specifically, the obstructing member 90 has an outer dimension 91when expanded to enable continuous contact with the air passageway innerdimension 51. This seals the air passageway upon placement of theobstructing member 90 in the air passageway 50 for maintaining the lungportion 66 in the collapsed state.

Alternatively, the vacuum need not be pulled in the lung portion 66.Rather, the lung portion 66, in accordance with a further embodiment ofthe present invention, may be collapsed by sealing the air passageway 50with the obstructing member 90. Over time, the air within the lungportion 66 will be absorbed by the body to result in the collapse oflung portion 66. In accordance with this embodiment of the presentinvention, the obstructing member 90 may be placed in the air passageway50 by utilizing catheter 70 as previously described but without pullinga vacuum or employing the inflatable sealing member 74.

Referring now to FIG. 8, it illustrates the ceiling or obstructingmember 90 in greater detail. The obstructing member 90 has a hollowcylindrical configuration. More specifically, the obstructing member 90includes a generally circular base 94 having an outer periphery 95. Theobstructing member 90 further includes a circumferential generallycylindrical sidewall 96 which extends from the outer periphery 95 of thebase 94. The generally cylindrical sidewall 96 has an outer surface 98which defines the outer periphery 91 of the obstructing member asillustrated in FIG. 7.

As previously mentioned, the obstructing member 90 is formed ofresilient material. For example, the obstructing member 90 may be formedfrom silicone rubber. This renders the obstructing member 90 collapsibleas illustrated in FIGS. 5 and 6 for feeding the obstructing member 90through the catheter 70 and causing the obstructing member 90 to expandwhen placed in the air passageway 50 for sealing the air passageway.

FIG. 9 illustrates the obstructing member 90 as described with respectto FIG. 8 but, in addition, includes an inner resilient reinforcementrib 100. The reinforcement rib 100 has a generally serpentineconfiguration and is in contact with the inner generally cylindricalsurface 102 of the obstructing member 90. The reinforcement rib 100serves to add increased structural integrity to the obstructing member90. In addition, the base 94, the generally cylindrical sidewall 96, andthe resilient reinforcement rib 100 are all collapsible. Thereinforcement rib 100, when the obstructing member 90 is positioned inplace within the air passageway 50, forces the cylindrical sidewall 96radially outwardly to form the generally circular base 94 and thecircumferential generally cylindrical sidewall 96.

FIG. 10 illustrates the obstructing member 90 in its fully collapsedstate. Here it may be seen that the base 94, when collapsed, isgenerally conically shaped to assist in the placement of the collapsedobstructing member in the main channel of the conduit. Also, as can beclearly seen in FIG. 10, the resilient reinforcing rib 100 is collapsedand ready to expand the obstructing member 90 by forcing the cylindricalsidewall 96 radially outwardly.

Referring now to FIG. 11, it shows, in accordance with a further aspectof the present invention, an obstructing member 110 which is similar tothe previously described obstructing member 90 but which includes aone-way valve. More specifically, the obstructing member 110 includesthe generally circular base 94, the generally cylindrical sidewall 96,and the reinforcement rib 100. In addition, the base 94 is slit asillustrated at 104 to form a valve structure. A tether 106 is connectedbetween the reinforcement rib 100 and the base 94. Hence, whenpositioned in the air passageway 50, the one-way valve structure of theobstructing member 110 permits air to flow in the direction indicated bythe arrow 108 but precludes airflow in the opposite direction. Hence,when the obstructing member 110 is placed in the air passageway 50, itis so placed in accordance with this aspect of the present inventionthat it permits air to be exhaled from the lung portion to be collapsedbut precludes air from being inhaled into the lung portion to becollapsed.

The one-way valve obstructing member 110 may be utilized in accordancewith the embodiment wherein a vacuum is pulled within the lung portionto be collapsed or in accordance with the alternative embodiment whereinthe air passageway is obstructed without the pulling of a vacuum in thelung portion to be collapsed. Because the one-way valve obstructingmember 110 permits exhaled air to flow therethrough, the lung portion tobe collapsed will be collapsed more quickly due to the reduction inresidual air within the lung portion to be collapsed.

Referring now to FIGS. 12 and 13, they illustrate another one-way valveobstructing member 120 which may be utilized in accordance with thepresent invention. Like the previous obstructing members, the one-wayvalve obstructing member 120 includes a generally circular base 94 and acircumferential generally cylindrical sidewall 96. The obstructingmember 120 further includes the reinforcement rib 100. To form thevalve, the base 94 includes a slit 122. On either side of the slit 122is a tether 124 and 126 which extend to the resilient reinforcement rib100. As a result, the one-way valve structure opens to air flow in thedirection indicated by arrow 128 but precludes air flow in the oppositedirection. The one-way valve obstructing member 120 may thus be employedin the same manner as the one-way valve 110 as described with referenceto FIG. 11.

As can thus be seen from the foregoing, the present invention provides adevice, system, and method for treating COPD by lung volume reduction.The lung volume reduction is achieved through the permanent collapsingof one or more lung portions, or lobes, or portions of lobes. Theforegoing is achieved without surgery. Following the treatment, the lungtissue within the thorax will occupy a lesser volume than previouslyoccupied providing room for the diaphragm to assume its arcuate state toassist in normal breathing and to achieve the benefits of lung volumereduction.

While particular embodiments of the present invention have been shownand described, modifications may be made, and it is therefore intendedin the appended claims to cover all such changes and modifications whichfall within the true spirit and scope of the invention.

What is claimed is:
 1. A method of reducing lung size of a lung, themethod including obstructing an air passageway communicating with aportion of the lung, the obstructing step including the step of placinga one-way valve in the air passageway to permit air to be exhaled fromthe lung portion and to preclude air from being inhaled into the lungportion for collapsing the lung portion.
 2. The method of claim 1including the further steps of inserting a conduit into the airpassageway communicating with the lung portion and pulling a vacuum inthe lung portion through the conduit.
 3. The method of claim 2 whereinthe conduit includes an outer surface, and wherein the step of pulling avacuum includes sealing between the outer surface of conduit and the airpassageway.
 4. The method of claim 2 wherein the step of placing theone-way valve in the air passageway is performed after the pulling ofthe vacuum.
 5. A method of reducing lung size of a lung, the methodincluding the steps of: inserting a conduit down a trachea, into amainstem bronchus, into a bronchial branch, and into a bronchialsub-branch communicating with a lung portion of the lung to be reducedin size; feeding a one-way valve down the conduit; and deploying theone-way valve in the bronchial sub-branch so that air is permitted toexit the lung portion while being precluded from entering the lungportion and causing the lung portion to collapse for reducing the sizeof the lung.
 6. The method of claim 5 including the further step ofremoving the conduit after deploying the one-way valve in the bronchialsub-branch.
 7. The method of claim 5 including the further step ofpulling a vacuum in the lung portion through the conduit.
 8. The methodof claim 7 wherein the conduit includes an outer surface, and whereinthe step of pulling a vacuum includes sealing between the outer surfaceof the conduit and the bronchial sub-branch.
 9. A method of reducinglung size of a lung, the method including the steps of: inserting aconduit down a trachea, into a mainstem bronchus, into a bronchialbranch, and into a bronchial sub-branch communicating with a lungportion of the lung to be reduced in size; pulling a vacuum in the lungportion through the conduit to collapse the lung portion; and deployingan obstructing member in the bronchial sub-branch to preclude air frombeing inhaled into the lung portion through the bronchial sub-branch.10. The method of claim 9 wherein the deploying step includes feedingthe obstructing member down the conduit and into the bronchialsub-branch.